Hi, Following the OCCI-WG session in Madrid and my presentation at the workshop, please find here the link to the work I've done on XML representation of OCCI. The presentation: http://fr.slideshare.net/JeanParpaillon/occi-xml-description The schemas and examples: https://github.com/jeanparpaillon/occi-schemas The objective is to be able to describe in a formal way the OCCI extensions, independantly from implementation languages (Python, Ruby, Java, etc). Basic architecture: - XSD describe OCCI types XML representation - OCCI extensions are described with XML files, validated with XSD. - OCCI representation can be validated with above XML file, which is not an XSD. Nervertheless, XML extension file is formal enough for implementation to validate rendering. For attribute types (string, numbers, etc.), we use the XML schema type model to describe them. For instance, a mac address is described with: <xs:simpleType name="mac802"> <xs:restriction base="xs:string"> <xs:pattern value="[\da-fA-F]{2}(\:[\da-fA-F]{2}){5}" /> </xs:restriction> </xs:simpleType> Your comments are welcome, -- Jean Parpaillon Open Source Consultant Phone: +33 6 30 10 92 86 im: jean.parpaillon@gmail.com skype: jean.parpaillon linkedin: http://www.linkedin.com/in/jeanparpaillon/en